Find the period of the function. y = -3 cos x

  best answer for the question.1.     divide  7/24  by  35/48  and reduce the quotient to the lowest fraction. 

Rewrite the following without an exponent. (5/8)-1

You were told that the amount of time lapsed between consecutive trades on the new york stock exchange followed a normal distribution with a mean of 15 seconds. you were also told that the probability that the time lapsed between two consecutive trades to fall between 16 to 17 seconds was 13%. the probability that the time lapsed between two consecutive trades would fall below 13 seconds was 7%. what is the probability that the time lapsed between two consecutive trades will be between 14 and 15 seconds?